Welcome Elektor Readers!

You are invited to receive this fun little 10-in-1 project kit FREE with your self-addressed stamped envelope! Just follow the instructions on our “How Can I Get It?” page, but don’t send money, just include a small note with the words ””Free Kit Offer for Elektor readers” written on it. Please allow us 4 weeks for delivery (we have a lot of these to make!).
And when you’re done, skip over to our forum to let us know how it turned out!~ From your friends at PAiA.

WHAT IS THIS, HOW CAN I MAKE IT?Simple Electronic Kit #1: 2-Transistor Ribbon Kit

We're going to show you how to make the world's most bare-bones electronic music instrument – and a bunch of other things, as well.

This instrument is called a 'ribbon controller', but it's also known after its inventor, Paul Tanner, as a 'tannerin'. He called this instrument an 'Electro-Theremin'. That name didn't catch on because this is not a Theremin (the musical instrument you control by moving your hands in the air) even though it sounds like one. You are going to build a sound generator that changes pitch as you slide wires back and forth on a conductive “ribbon” we will make as part of this project..

We also discuss how you can take this same circuit and do many other experiments with things you have around your home.

Brian Wilson and the Beach Boys' song “Good Vibrations” used the magic of Paul Tanner's ribbon controller to make its distinctive sweeping wee-oo-wee sound. Wikipedia has a great page on the history of the ribbon controller: http://en.wikipedia.org/wiki/Electro-theremin

HOW DO I GET ONE?

If you aren't holding one of our “2-Transistor Ribbon Kits” in your hand, keep reading. We'll explain how to make your own kit, or how to get one from us for about the cost of a can of soda.

If you do have the kit, this page will teach you about your kit, show you how to hook it up and talk about several experiments you can do with parts around the house.

Briefly, the circuit (called a relaxation oscillator) measures resistance and creates an audio tone to match. The value of the resistance determines how fast a capacitor charges. Once the capacitor gets enough charge, the transistors turn on. This causes the speaker to 'pop' and it also forces the transistors to turn off (relax!). The capacitor then starts to charge up again, repeating the cycle all over again (oscillation).